Nancy looked around for her friend George Fayne. George was the captain of the soccer team. She would help Amara. But George was not in the locker room.

All the other girls on the team watched as Nancy got up and walked over to Amara.

"Let me see," Nancy said.

Amara was sitting on a wooden bench in the locker room. School was out for the day. Now the third-grade girls' soccer team was getting ready for practice. Backpacks and jackets were scattered all over the place.

"I don't want to touch it," Amara said. She stuck out her foot to show Nancy.

"I can't see anything," Nancy said. "You'll have to take off your shoe."

Amara wrinkled up her nose and made a face. But she took her shoe off She used only two fingers of each hand; so she wouldn't have to touch it much.

When she pulled her shoe off, all the girls in the room said, "Eewww! Gross!"

"I know," Nancy said with a nod. "Someone let the air out of Julia's ball on Friday, too."

"You're a detective, " Lindsay said. "Maybe you can figure out who's doing this -- and who put the icky stuff in Amara's shoe."

Maybe I can, Nancy thought. At least I can try.

She saw Carrie Rodis walking ahead of them all by herself. Nancy had noticed that Carrie had ignored Amara. She hadn't seemed to care about the goo in Amara's shoe. Was Carrie the one trying to hurt the team?

There was no way to know for sure. But someone had been playing tricks on the soccer team. And Carrie had a good reason to do it.

Before she had moved, Carrie had played for the Lions. They were another elementary school team. And they were the Tigers' biggest rivals!

Maybe Carrie still wants the Lions to beat us, Nancy thought. Maybe she's trying to make our team look bad so that her old friends will win.

"Hey, Nancy! Lindsay! " a voice called.

Nancy and Lindsay turned around and saw George running toward them. Her dark curls bounced as she ran. Her long legs carried her quickly across the field.

"Where were you?" Nancy asked.

"I couldn't find my shin guards," George answered. "I thought maybe I left them in my cubby, so I went back to see. But they weren't there. Finally I found them in the trash."

"You're kidding!" Lindsay said.

George shook her head. "Someone must have taken them out of my backpack."

"Something else happened in the locker room today," Lindsay said quickly. She loved to be the first one to tell stories.

"What are you talking about?" George asked.

Lindsay told George about the yucky stuff in Amara's shoe. George frowned. She looked down at her shin guards. "I think it was Carrie."

Nancy was surprised that George suspected Carrie, too. She didn't want to say that in front of Lindsay, though, so she said, "But she's a good player."

"Who cares?" George said. "She acts like she's the only one who's any good. She's always telling me how to pass the ball. Like I don't already know."

The three girls started walking toward the field again.

Nancy squinted. Carrie was kicking a soccer ball. It flew into the air and went into the goal. It was a good shot. It would have been hard for a goalie to catch it.

"She's one of our best players, " Lindsay said.

George made a face. "So what," she said.

Just then a cheer went up from the sidelines. Nancy looked across the field.

Two girls were standing there. They were watching the team play.

The ball rolled toward Carrie, and she kicked it again. Again it sailed into the goal.

"Way to go, Carrie!" the girls on the sidelines yelled.

"Who are they?" Nancy asked. "I don't recognize them."

"I do," George said in a grouchy voice.

"Well? Are you going to tell me?" Nancy asked.

"That's Margot Bachwood and Tonya Morris," George said. "I remember them from last year's games. They're two of the best soccer players on the Lions team. And the Lions are our team's worst enemies!"